Feeble DM-SM interaction via new scalar and vector mediators in rotating neutron stars

Abstract

We investigate the possible presence of dark matter (DM) in massive and rotating neutron stars (NSs). For the purpose we extend our previous work [1] to introduce a light new physics vector mediator besides a scalar one in order to ensure feeble interaction between fermionic DM and β stable hadronic matter in NSs. The chosen masses of DM fermion and the mediators and the couplings are consistent with the self-interaction constraint from Bullet cluster and from present day relic abundance. Assuming that both the scalar and vector mediators contribute equally to the relic abundance, we compute the equation of state (EoS) of the DM admixed NSs to find that the present consideration of the vector new physics mediator do not bring any significant change to the EoS and static NS properties of DM admixed NSs compared to the case where only the scalar mediator was considered [1]. However, the obtained structural properties in static conditions are in good agreement with the various constraints on them from massive pulsars like PSR J0348+0432 and PSR J0740+6620, the gravitational wave (GW170817) data and the recently obtained results of NICER experiments for PSR J0030+0451 and PSR J0740+6620. We also extend our work to compute the rotational properties of DM admixed NSs rotating at different angular velocities. The present results in this regard suggest that the secondary component of GW190814 may be a rapidly rotating massive DM admixed NS. The constraints on rotational frequency from pulsars like PSR B1937+21 and PSR J1748-2446ad are also satisfied

Consequences of neutron decay inside neutron stars

“…However, it is generally agreed that for the majority of neutron stars typically 90% of the matter consists of neutrons, which makes neutron stars ideal candidates to test the hypothesis of neutron decay into DM. If neutrons do decay into dark matter a neutron star should contain enough dark matter particles to change the neutron star properties [31,32,[67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84]. To model the nuclear matter in a neutron star an equation of state based on the quarkmeson coupling (QMC) model is adopted [85][86][87][88].…”

Second Love number of dark compact planets and neutron stars with dark matter

“…At the same time, self-annihilating DM accreted onto neutron stars may significantly change their kinematical properties [19] or provide a mechanism to seed compact objects with longlived lumps of strangelets [20]. Furthermore, neutron stars that accommodate non-self-annihilating DM have emerged as an interesting astrophysical scenario for analyzing the effects of DM on hadronic matter (or even quark matter) under extreme conditions [16,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. In this context, the existence of compact objects with Earth-or Jupiterlike masses but unusual small radii has been put forward [40][41][42], allowing for a new scenario to determine the existence and nature of DM.…”

Consequences of neutron decay inside neutron stars

“…However, it is generally agreed that for the majority of neutron stars typically 90% of the matter consists of neutrons, which makes neutron stars ideal candidates to test the hypothesis of neutron decay into DM. If neutrons do decay into dark matter a neutron star should contain enough dark matter particles to change the neutron star properties [32,33,[68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85]. To model the nuclear matter in a neutron star an equation of state based on the quark-meson coupling (QMC) model is adopted [86][87][88][89].…”